Method for preparation of metal salts of methyl phosphonic acids

Abstract

The present invention provides a process for producing a metal or metalloid salt of methyl methy phosphonic acid which comprises reacting, under non-aqueous conditions, dimethyl methylphosphonate with a finely divided form of an oxide or hydroxide of one or more metals or metalloids from group IIA, IIB, IIIA, IVA, IVB, VA, VIB, VIIB or VIII of the Periodic Chart of Elements, at an elevated temperature.

We claim: 
     
       1. A process for producing a metal or metalloid salt of methyl methylphosphonic acid which comprises reacting, under non-aqueous conditions, dimethyl methylphosphonate with a finely divided form having particles of an average size below 2 microns, of an oxide or hydroxide of one or more metals or metalloids from group IIA, IIB, IIIA, IVA, IVB, VA, VIB, VIIB or VIII of the Periodic Chart of Elements, at an elevated temperature. 
     
     
       2. A process as claimed in claim 1 in which the reaction temperature is from 100° C. to 200° C. 
     
     
       3. A process as claimed in claim 2 in which the reaction temeprature is from 160° to 180° C. 
     
     
       4. A process as claimed in claim 1 in which the reaction is carried out using excess dimethyl methylphosphonate as solvent, or a high boiling inert solvent. 
     
     
       5. A process as claimed in claim 1 in which the metal or metalloid is magnesium, calcium, barium, zinc, boron, manganese, molybdenum, aluminium, silicon, tin, lead, titanium, antimony, iron or cobalt. 
     
     
       6. A process as claimed in claim 5 in which the metal or metalloid is magnesium or aluminium. 
     
     
       7. A process as claimed in claim 1 in which the oxide or hydroxide has an average particle size below 1 micron. 
     
     
       8. A process as claimed in claim 5 in which the oxide or hydroxide has an average particle size below 1 micron. 
     
     
       9. A process as claimed in claim 8 in which the metal or metalloid is magnesium or aluminum.